ls67ss

hello i have a 96 e320 with straight 6 and a auto trans.first issue is i have a bad draw battery will not last over night i had test light hooked up between post and cable light is on bright i pulled every fuse from under hood,side of dash and by battery one by one with everything closed i cannot get the light to go out.any ideas .2nd issue my instrument cluster works when it wants to when working works great sometimes nothing in cluster will work i checked all fuses and connector to cluster everything looked good any ideas .3rd issue the small headlight on drivers side will not work says lamp out in dash.i tested for power no power on the white wire followed to the plug no power all fuses are good not sure why that one only has no power.if anyone has ran into any of these any help is apreciated thank you